Fuel pump of reversed type



- JaIL 3, 1933- A. M. BABrrcH E1- AL 1,893,218

FUEL PUMP OF REVERSED TYPE Filed Dc. 13,y 1929 Patented Jan. 3, 1933 UNITED' STATES PATENT ori-ICEv 1- ABRAHAM M. BABITOH AND GORDON W. HARRY, OF FLINT, MIOHIGAN FUEL PUMP OF BEVER-SED TYPE Application led December 13, 1929. Serial No. 413,768. A

This invention relates. to variable stroke fuel pumps' for use upon the engines of automotive Vehicles, and the like; and it is referred to as of a reversed type for .the

reason that (contrary to the usual arrangep ment) the variable-volume pump chamber is placed belowthe reciprocatory pumping element rather than above it,-the inlet opening and the outlet opening of said chamber being at a slightly lower level still. The pumping element is preferably a diaphragm; and reciprocatory movement may be conditionally imparted thereto (wherever the. built-up pressure falls below a predetermined level) through a slidable handling element and by means disposed entirely above said diaphragm,said means including a spring or pair of compression springs. These springs are preferably so housed within a novel cap as to facilitate assembly and inspection and to obviate risk of detrimental eects due to any collection of heavy deposits, or any freezing of water, about said spring or springs or said diaphragm.

Compactness and facility-of assembly, of inspection and of replacement of parts are important objects of the present invention#- in which a lter'unit may be disposed directly below pump parts; and advantageous embodiments thereof may accordingly include (in addition to a pair of structural elements cooperating in the retention of a pump diaphragm, one of said structural elements bef ing preferably flanged suitably to its lateral attachment to a crankcase, or the like) not only means facilitating the separate removal of the mentioned cap and/or the mentioned l cup but means facilitating the separation of said structural elements, as occasion may require,-without disturbing said cap or said cup. v

It is a further object of this invention to provide a fuel pump, preferably of the selflimiting type above referred to, in which valves are located directly beneath the diaphragm and below the pump chamber in such manner as to obviate detrimental effects due to any accumulation off-vapor in the region of said valves,-the stroke imparted to the diaphragm being dependent upon the pressure built up therebelow. The position of said valves is intended to be such .as to assure, with a given length of stroke, a sub-r stantially corresponding advance of fuel past said valves; and the passages to and from' 55 and between the mentioned -valvesare accordingly reduced to a minimum in length.

It isA a further object of this invention economically to provide suitable seats for easily and reliably operated valves, said valves being preferably loaded by light and calibrated springs, which may be retained by suitable bosses,-said seats being preferably provided, in a novel manner,`with gasket elements which obviate. leakage externally past the same; andfall main strucy tural parts may be inexpensively die-cast and held together by bolts and/orscrews, as

illustrated. p

Further objects of this invention, including various details pertaining to construction and to reliability of action, may be best appreciated from the following descriptions,i

Figure 1 may be referred to as a substantially median vertical section through one type of pump illustrative of the present in- ,taken in connection with the appended claim and the accompanying drawing. 75

vention, various optional features being ineluded. v

Figure 2 is'a top plan view of the embodimentshown in Figure 1, but with certain parts broken away and certain optional features omitted. y

` Figure 3 is a horizontal sectional view, taken somewhat as suggested by broken line 3 3 of Figure 1.

Figure 4 is, for the most part, a-sectional view corresponding to the central portion of Figure 1, but taken from a different angle and showing certain features of modification` hereinafter described,-an intermediate chamber-providing element 'being shown as cast' in onepiece.

Figs. 5, 6 and 7 are partial vertical sections showing alternative details.

Referring first tothe more general features shown in Figures 1, 2 and 3, a chamberproviding intermediate structural elementl 10 is shown as cooperating :with a flanged upper structural element 11 in the retention of a reciprocatory pumping element in the form of a diaphragm 12, manipulable by a handling elementin the form of a'slidable rod 13; and expulsion strokes may be imparted thereto by means such as one of a pair of compression springs 14, 15 retained by means such as a cap 16 having they general form of arr inverted pocket. This may be rovided with an inclined flangev 17, cooperating with a correspondingly inclined surface provided upon the flanged structural element 11 and retained by means of screws 18.

Below the mentioned parts there is shown -a filter cup '19, retained by means including a pivotally movable Wire bail 20, a conical element 21, and a screw 22 provided with a milled nut 23,-these features being immaterial to the present invention and fuel being admitted thereto through a central inlet passage 24 in such manner that, to exit therefrom into a pump chamber 25, it must pass through a strainer or strainers held by a gasket in a known way.

An inlet passage 26, 26 to said chamber is shown as controlled by a valve 27; an outlet passage 28, 28 is shown as provided with a valve 29; and intake' strokes may be imparted to the diaphragm 12, or its equivalent, by means such as a suitable sectional lever or actuating finger F. This is shown as comprising an outer section 30, including a motion-receiving arm 31 whichis engageable by a rotating or other cam 32, in a known manner, and an inner arm 33, under,the constant Y pressure of the mentioned spring 15, or qits equivalent, and also an inner section in the form of a link or a pairof links 34, 34,- slidably or otherwise connected with the diaphragm stem 13 by means of"a pin 35. The mentioned lever sections are shown as pivoted upon an identical fixed pin 36; and the links 34, 34 are shown as provided with curved surfaces 37, terminating in Hat surfaces 38, which are adapted to engage corresponding at surfaces 39, provlded upon the lever section 30, whenever the pressure within the pump chamber 40 falls to av value sufficiently low to enable the spring 14 to depress the mentioned movable parts connected with the diaphragm 12 or the stem 13 to substantially the positions in which they are shown.

will be seen absolutely to preclude the accu- `in connection with intake valve 27a.

expedients. These expedients may include the insertion of a brous packing element at 42 and/or the provision of an inclined drainage surface, as at 4 3, to Apermit return of any condensed liquid through an opening 44,-- such as may beprovided in crankcase 45,l to permit reeiprocation of the mentioned lever, or any suitable lever, therein. The chamber 41- may also be provided, as'at 46, with an opening to the external air.

Although Figure 1 shows-the structural element l0 as comprising an upper portion 10a, formedseparately from a lower portion 10b, the latter being provided with an annular seat 47 for the filter cup 19 or for an interposed gasket 48, it is suggested inFigure `4 that the mentioned parts may be integrally formed orincluded in a single die-casting 10ab'. In' the form last referred to, gasoline entering through the passageV 24a and descending into a filter cup (not therein shown) may rise past a valve 2 7ainto a pump chamber 40a, descending therefrom past a valve 29a to an outlet passage 28a,-

all of the mentioned passages being formed in the mentioned die-casting 10a?) and valve seats being provided in any suitable Way. For example, a separately inserted seat element 49a,'is shown as threaded and as engaging a gasket 50a; and a staked seat element 51a is shown as somewhat similarly engaging a gasket 52a,-the mentioned gaskets serving to prevent leakage around the respec-- tive valve seats; and an apertured stamping* 53a is optionally employed to provide a retaining boss for a calibrated spring 54a, used An analogous spring 55a is shown as surroundmulation of any troublesome liquid in contact with the springs 14,15; and admission ofsuch liquids to a chamber 41, above the diaphragm 12 may be substantially prevented by sultable ing an integrally formed boss 56a, below the valve 29a; and, merely to illustrate the possibility of supporting the entire organization from either of the mentioned structural elements, the element 10a?) is shown as provided with a. crankcase-engaging lange`57a, suit ably apertured for the reception of retaining bolts or screws 58a.

Returning novvr to Figures 1 and 2, in case the structural element 10 is formed in two parts, it will be seen thatthe respective Wells in whichthe valves 27 and 29 are retained may be formed by oppositely extending hollow bosses 59 and 60, one of these being formed upon each of the cooperating parts 10a and` 10b. Said bosses should be substantially- 'equal in length, interiorly machined and adapted snugly to receive oppositely-extending valve-seat bosses, and adaptedl to reta-in leakage-obviating gaskets 50 and 52, corre? sponding in functionto the mentioned gaskets 50a and 52a; and, in this instance, the respective valveseats 49 and 51 may be economically formed integrally with the respective parts 10a and 10b of the ehaiberproviding structural element 10. Spaeed bolts or, screws 18', holding these parts together, may be distinct from cap-retaining screws 18 and also from diaphragm-retaining screws or bolts Figure 5 suggests the use of a reciprocatory operating member in the form o f a, onepiece lever 30346, replacement of spring 15 by a spring 156, and the use of a screw 616, provided with a special head 626 (adapting it to be automatically or manually manipulated and/or to be sealed in an adjusted position) in predetermining a limit of pressure applicab-le by a spring 146,-said screw being shown as seated in the top of a cover element 166, formed of sheet metal. The adjustment of this screw, if provided, will naturally depend upon various circumstances and especially upon .the type of installation in which the described pump is to be employed; but it should be understood not only that these last-mentioned features are optional and relatively unimportant but that various features of this invention may be independently used and also that numerous modifications, additional to those suggested herein, might easily be devised,-all without departure 'from the scope of the present invention'. For example, in theform last reerred to, the l cover element 166 may be formed integral with a main structural element, spring 156 being then vertically inserted in advance of screw 616; or a very simple construction using but one spring or 15d somewhat as suggested in Fig. 6 or Fig. 7 may be found satisfactory in, for example, cases whereA the very `slight sound (sometimes caused by successive engagements of a circular or other cam with a lever 30346 or with an operating member in the form of a,

um tappet 303.403, shown as secured by nuts 63d,

64d 'on a slidable-handling element 13d and adapted to extend above a rotary not be objected to. We claim:

In a fuel pump for lateral application to a crankcase pro'vided with an opening through which extends an operating member: a pair i of structural elements which cooperate in the retention of a diaphragm pumping element; a slidable handling element extending up- .'ward from said diaphragm element and engageable by a section of said member; and recam) may .silient means thereabove tending td holdsaid member against a cam and to depress said diaphragm,-the upper structural element being provided with means for drainage into said crankcase.

IIn testimony whereof we affix our signatures. i

r GORDON W. HARRY.

ABRAHAM M. BABITCH'.r 

